The present invention is directed to an insulation jacket. More particularly, the present invention pertains to an improved, protective, metal insulation jacket having an improved elbow bend configuration.
Pipes and/or machinery are often insulated with fiberglass, polyurethane or other similar materials. The insulation which covers the pipe often requires metal covers or jackets to be placed over the insulation to preserve and protect the insulation material itself.
Covering linear pipe with metal is relatively simple: a flat metal sheet is wrapped concentrically around the linear cylindrical portion of pipe and secured with strap or fasteners. Linear portions of pipe may be covered with, for example, 1000 or 3000 series aluminum.
Protecting the turns and bends in the pipe, such as at angled portions, tees, or elbows, can be difficult, however. Corner or elbow portions of pipes are typically covered using the softer or more malleable 1000 series aluminum to facilitate wrapping around the bend portion. Preformed metal jackets are also used to protect angled pipe. A flat metal sheet is press or punch molded in two, generally semi-circular, angled portions. Each portion is wrapped around opposing sides of the pipe and the seams are joined by, for example, welding, screws, and/or straps.
The mold for such elbow jackets is generally made from composite, steel, or similar materials, and have three or more random, finger-like indentations present to compensate for excess metal bunching or accumulating at the inner curvature of the angle or elbow during the pressing or punching process.
The malleability of 1000 series aluminum used for the preformed jackets, however, also makes the jacket more susceptible to dents. Additionally, the material tends to accumulate or bunch at the inner elbow, as shown in FIG. 1, creating creases or folds F and gaps G. Folds and gaps can be unsightly and can act as an accumulation location for dirt and debris to be trapped in the jacket, aiding corrosion and deterioration of both the protective metal covering and the underlying insulation.
As discussed above, while angled portions are protected with 1000 (temper 0, fully annealed) series aluminum jackets, linear portions of insulated pipe are protected by jackets made from a more durable 3000 series, H12 or H14 aluminum, or stainless steel (SS304 and SS316 or similar). Thus, at times there are portions of pipe that have transition areas such as at elbows made from 1000 series aluminum, while the remaining portions are, for example, 3000 series aluminum, in one stretch of pipe. Having multiple types of metal in a length of pipe produces non-uniformity in jacket coverings, as well as different maintenance schedules and fastening systems.
Additionally, while the mold for the angle or elbow portions is suitable for use with softer metals such as 1000 series aluminum, the same mold cannot be used with harder metals, such as 3000 or 5000 series aluminum or SS304 and SS316 stainless steel. Harder metals have a tendency to crack under the stresses produced by the configuration of these molds on the such harder materials.
Furthermore, in addition to the mold having undesired affects on the harder metal, the material itself is not as malleable as the 1000 series counterpart and is difficult to bend and mold. Thus, both the elbow mold and the type of material used have been relegated to 1000 series aluminum and molds with 3 or more fingers to accommodate extra material.
Accordingly, it would be desirable to have an elbow jacket made from more durable metal, such as 3000 series aluminum or harder or stainless steel. Also desirable is a mold for making such a protective jacket for other than straight sections of pipe.